Biology of primary breast cancer in older women treated by surgery: with correlation with long-term clinical outcome and comparison with their younger counterparts

Background: As age advances breast cancer appears to change its biological characteristics, however, very limited data are available to define the precise differences between older and younger patients. Methods: Over 36 years (1973–2009), 1758 older (⩾70 years) women with early operable primary breast cancer were managed in a dedicated clinic. In all, 813 underwent primary surgery and 575 good quality tumour samples were available for biological analysis. The pattern of biomarkers was analysed using indirect immunohistochemistry on tissue microarrays. Comparison was made with a previously characterised series of younger (